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Published January 2008 | public
Journal Article

Radial Differential Mobility Analyzer for One Nanometer Particle Classification


We present details on the design, construction, and calibration of a radial differential mobility analyzer suitable for sizing aerosol nanoparticles with mobility diameters as small as one nanometer. Design improvements targeted decreasing the residence time with a concomitant reduction in particle agglomeration and diffusional losses to walls. Calibration was performed using aerosolized monodisperse molecular ions. Instrument resolution was found to increase with applied voltage as V^1/2, indicating that diffusion is broadening the transfer function and reaching a value of ~7 for the largest molecular ion measured (mobility diameter of 1.47 nm). The mobilities of three molecular ions in the tetra-alkyl ammonium halide homologous series are also reported.

Additional Information

© 2009 Copyright American Association for Aerosol Research. Received 10 June 2008; accepted 9 September 2008. This work was partially supported by the Jacobs Institute for Molecular Engineering and Medicine at Caltech. An NSF graduate fellowship to NAB is also acknowledged.

Additional details

August 19, 2023
October 17, 2023